Userdata

Userdata

What is a userdata?

A userdata is the type Lua uses for data structures in the underlying C program. There aren't native Lua functions for handling those types, they must be handled via metatables. All Roblox objects and events are userdata Lua type.

Using userdatas

You can create a new userdata with an empty metatable by passing true to the undocumented newproxy function. This userdata cannot be used for anything other than invoking functions via its metatable.

Example

local ud = newproxy(true) -- new userdata with an empty metatable
getmetatable(ud).__index = {Foo = "Bar"} -- index metamethod
print(type(ud), ud.Foo)

Output:
userdata: 0x631fc8	Bar